January 20, 2009 Dr. Catherine Keske Dr. Sybil Sharvelle Anaerobic Digestion: Turning One Man’s Trash Into Another Man’s Treasure January 20, 2009 Dr. Catherine Keske Dr. Sybil Sharvelle

Recovering Manure to Produce Energy Benefits of Anaerobic Digesters How Digesters Work Trends and Feasibility Economic Issues How to Get Involved or Learn More Questions With all of the regulation and controversy surrounding manure management, it’s sometimes hard to think of manure as a “treasure trove”. However, through anaerobic digestion, we can convert manure from confined feeding operations into energy that can be used on the farm. This is particularly beneficial to dairies, which require a gIn many cases, extra energy can be supplied back to the grid. Even though the practice was first implemented in the 1970’s, updated engineering technology can convert waste into energy source with greater technical and economic efficiency than in the past. Dr. Sybil Sharvelle is a civil engineer from CSU, and she has conducted a significant amount of research on this process at Purdue in Indiana, where she earned her doctorate. She is going to speak about how these devices work in the Intermountain West. She will also speak about several of the trends in anaerobic digestion.

Benefits of Anaerobic Digesters Environmental Economic and Social Production Soil management Manure management Biogas production Reduces environmental pollution Water Green house gases Ammonia On-farm energy generation (avoid electricity purchases) May sell energy to utilities Savings on bedding Sale of composted solids Carbon credits available Renewable energy certificates Odor control Bedding savings: If a farm uses a solids separator, solids may be sold for bedding or used to replace current bedding materials. Farms that switch from an anaerobic manure lagoon to a digester are eligible for carbon credits if the digester reduces methane emissions. (PA—4.41 carbon credits/lactating cow per year).

Anaerobic Digestion: How It Works Green Power Anaerobic Environment Cogeneration CH4 Organics  Acids Acids  CH4 High BOD Waste Hot Water High Nutrient Low Odor Waste

ADM Soybean Processing Model Project: Quadra Project in Indiana Green Power Frito Lay Biodiesel Plant WE Can Do This in Colorado Too! Cold Soybean Oil Food Waste Anaerobic Digester Hog Waste Hot Soybean Oil ADM Soybean Processing

Waste Suitablility Low solids content, < 14% solids Low inorganic content Soil Rocks Higher organic content, more energy content

Colorado – Cold Climate Average Annual Minimum Temperature

Covered Lagoon – Not an Option

Average Annual Precipitation In Colorado Colorado – Dry Climate Average Annual Precipitation In Colorado Need to Find Nearby Source of Wastewater or Add Groundwater to Waste

Successful Digester at Dairy in Montana

Alternative Design - Two Stage Leachate Collection Low Moisture Manure and Other Waste Organics Anaerobic Digester High Organic Leachate Methane Gas

Costs of Anaerobic Digesters Cost of the digester: Approximately $1 million Average life: 15 yrs. (Range: 10-20) Cost of the solids separator: Approximately $75,000 **Key to raising profitability** Opportunity cost Cost of your next best alternative While the costs are high, it is also important to remember that “keeping the neighbors happy” (i.e. keeping the odors minimized) is also a benefit. Legal fees will significantly raise your operating costs. I like to remind people of this, as well.

Are Digesters Profitable? “Yes…” Several models show profitability Measured in cash flows associated with the investment Critical to use a solids separator Use the solids as a co-product Bedding is the most economic use Larger herds lead to economies of scale Key element to profitability: Energy prices 2,000

“…But…Will a Digester Work for My Operation?” Greater than 500 head (more than 1,000 head preferred) Requires steady flow of manure (CAFOs) Climate matters – the warmer the better Must be able to use the biogas “Community” digesters are an option Pipelines transport waste to central site Could consider other facilities (e.g. food processing)

“Yes, But…” Economic Considerations Majority of studies conducted in the East Profitability relies on carbon credits $2 per metric ton of CO2 “Net positive gain” may include a net gain to the environment (not necessarily a net gain to the farmer/rancher) Profitability critically depends upon energy prices

Want to Learn More? Contact Us! Institute for Livestock and the Environment: http://ile.colostate.edu USDA Producer Workshop 2/19/09 York, Nebraska AgStar: http://www.epa.gov/agstar/ Colorado Governor’s Energy Office: http://www.colorado.gov/energy/index.asp Sponsoring feasibility studies Contact us—we have several grant proposals pending and will begin implementing these programs in the very near future.

Questions?